Currently, aircraft equipped with at least three engines exist. At least two engines are situated at the underwing section of the aircraft while an additional engine, subsequently called the third engine, is situated at the vertical tail unit of said aircraft.
In the prior art, the presence of this third engine necessitates making a vertical tail unit in two parts. More precisely, a fin of said vertical tail unit is formed in two parts, each part separated from the other by an engine body. A bottom part of the fin, integral with the fuselage, carries the engine. Conversely, a top part of the fin, integral with said engine, is carried by the engine. Therefore continuity of a vertical tail unit body is not assured, since it is interrupted by the presence of the engine. At the location of the engine, it is therefore necessary to dispose frames, or panels, allowing the engine to be integrated to a general contour of the vertical tail unit, and allowing stresses to which the engine/vertical tail unit assembly is subjected to be at least partially taken up.
However, such a solution is difficult to implement. In addition, rigidity of the assembly is less than that of a one-piece vertical tail unit, that is, wherein a body is formed all in one block. Furthermore, assembly of the engine and the vertical tail unit according to the prior art considerably increases the general weight of said vertical tail unit.